Colorphotographic material

ABSTRACT

Photographic color images having extremely good light-fastness are formed by converting a silver halide image to an image of a salt of a heavy metal that complexes with an organic complexing agent to make a strongly colored diffusion-resistant complex more light-fast than color coupler dyes. The heavy metal can be copper, chromium, manganese, iron, cobalt, nickel, palladium or platinum, or the like, and the organic complexing agent can have two different locations in its molecule for coordination with the metal. The silver halide is converted to the salt of the complexing heavy metal by applying to the silver halide image a differently colored or uncolored reactive complex of that metal having a disassociation constant larger than the corresponding complex of silver, so that the silver of the silver halide becomes bound by the reactive complex and liberates the heavy metal. It is also possible to go through two such reactive complex treatments to first convert the silver halide image to a mercury salt image, for example, and then convert the mercury salt image to an iron salt image, before the strongly colored light-fast final complex is formed. The organic complexing agent can be uniformly distributed in a light-sensitive silver halide emulsion, or it can be uniformly distributed in a layer adjacent that emulsion. After light-fast complex is formed, the unused complexing agent in such a layer can be complexed with a different metal ion to form a different color suitable for masking.

United States Patent Frank et al.

[ 1 May 2,1972

[54] COLORPHOTOGRAPHIC MATERIAL AGFA-Gevaert Aktiengesellschaft,Leverkusen, Germany [22] Filed: Dec. 13,1967

[21] Appl.No.: 690,105

[73] Assignee:

[30] Foreign Application Priority Data Dec. 20, 1966 Germany 54426 [52]US. Cl ..96/54, 96/21, 96/72, 96/96 [51 Int. Cl "G031: 7/00 [58] Fieldof Search ..96/54, 90, 9, 7, 8, 95, 96, 96/55, 57, 72

[56] References Cited UNITED STATES PATENTS 3,196,014 7/1965 Rogers..96/57 3,081,167 3/1963 Goulston et al ..96/57 2,013,159 9/1935 Lierg..96/57 2,333,359 11/1943 Bunting .....96/57 2,415,626 2/1947 Coote..96/57 2,533,181 12/1950 Sargent.... .....96/57 2,533,182 12/1900Sargent... .....96/57 2,308,023 1/1943 Peterson ..96/54 2,333,12611/1943 Schwarc ..96/54 3,243,296 3/1966 Nasu et al. ..96/61 3,445,2305/1969 Francis ..96/90 Primary Examiner-William D. Martin AssistantExaminer-M. Sofocleous AttorneyConnolly and Hut:

[5 7] ABSTRACT Photographic color images having extremely goodlight-fastness are formed by converting a silver halide image to animage of a salt of a heavy metal that complexes with an organiccomplexing agent to make a strongly colored diffusionresistant complexmore light-fast than color coupler dyes. The heavy metal can be copper,chromium, manganese, iron, cobalt, nickel, palladium or platinum, or thelike, and the organic complexing agent can have two different locationsin its molecule for coordination with the metal. The silver halide isconverted to the salt of the complexing heavy metal by applying to thesilver halide image a differently colored or uncolored reactive complexof that metal having a disassociation constant larger than thecorresponding complex of silver, so that the silver of the silver halidebecomes bound by the reactive complex and liberates the heavy metal. Itis also possible to go through two such reactive complex treatments tofirst convert the silver halide image to a mercury salt image, forexample, and then convert the mercury salt image to an iron salt image,before the strongly colored light-fast final complex is formed. Theorganic complexing agent can be uniformly distributed in alight-sensitive silver halide emulsion, or it can be uniformlydistributed in a layer adjacent that emulsion. After light-fast complexis formed, the unused complexing agent in such a layer can be complexedwith a different metal ion to form a different color suitable formasking.

6 Claims, No Drawings COLORPHOTOGRAPHIC MATERIAL This invention relatesto a process for the production of color photographic images in whichthe image dye consists of an organic metal complex compound which isparticularly fast to light, and also relates to light-sensitivephotographic materials for carrying out this process.

By the term toning process" in this specification .is meant any processin which a silver image can be converted into a dye image of any desiredcolor. The silver images may represent color separation records, simplytermed blue, green and red separation records, and after conversion ofthe blue separation record into a yellow image, the green separationrecord into a magenta image and the red separation record into a cyanimage, copies of the original in true colors are obtained if the thelayers are brought into register. According to one toning process thesilver images of the separation records are treated with potassiumferricyanide to convert the metallic silver image into a silverferrocyanide image. Thereafter, the blue separation record may betreated with a solution of a lead salt, whereby the silver ferrocyanideis converted into insoluble lead ferrocyanide which, on furthertreatment with a chromate solution, is converted into yellow leadchromate which is very fast to light. The green separation record can betreated with a nickel salt, whereby nickel ferrocyanide is producedsilver images of the three color separation records are first convertedinto silver ferrocyanide by means of potassium ferricyanide. Treatmentwith a nickel salt leads to imagewise formation of nickel ferrocyanidein all separation records. The blue separation record is then treatedwith dicyandiamidine sulfate, a yellow nickel complex being formed. Thegreen separation record is treated in known manner withdimethylglyoxime, a red nickel complex being formed, and the redseparation record is treated with 1,2-diaminoanthraquinone- 3-sulfonicacid, a blue nickel complex being formed. In all cases, the nickel saltimage of each individual separation record must be reacted separatelywith the dye-forming agent, in this case with a solution of an organiccomplex forming agent. Although these processes have advantages in thatthe dye images are considerably superior in their light-fastness toconventional color photographic images which contain azomethine dyesproduced by means of color forming developers, they have hitherto notcome into general use owing to the complicated procedure for making thecolored images. The main drawback is that a process of that kind washitherto not suitable to produce a dye image in true colors in amultilayer photographic material which contains all partial images.

It is among the objects of the invention to provide novel processesbased on the above toning processes which allow a simple processing andproduction of dye images in three-layer photographic materials.

We now have found that dye images which are very fast to light, andwhich consist of colored heavy metal complex compounds can be producedin simple manner. This is achieved by reacting silver halide which isimagewise distributed in a photographic emulsion layer with a solutionof a first complex compound of a heavy metal of the auxiliary groups ofthe periodic system of elements, excepting silver, with complex formingagents (ligands). The dissociation constant of this first complexcompound is greater than that of the corresponding complex compound ofthe same ligands with silver. In other words, these ligands form a morestable complex compound with silver ions than with the heavy metal ionsof the first complex. Free heavy metal ions are liberated imagewise fromthe first complex compound by reaction with the imagewise distributedsilver halide. These free heavy metal ions are capable of forming acolored complex compound with organic complex forming compounds.Therefore, the photographic materia] of the instant invention containsin addition to the imagewise distributed silver halide such an organiccomplex forming compound which is uniformly distributed anddiffusion-fast incorporated in the silver halide layer or another layeradjacent thereto and which is incapable of reacting with silver halide.The colored heavy metal complex compound of the final image is formedonly at those areas of the layer, which correspond to the silver halideimage, i.e., at those areas where free heavy metal ions have beenliberated. No reaction must occur between the organic complex-formingcompound in the layer and the first complex compound which contains theheavy metal in complexed form. Therefore it is an important requirementthat the dissociation constant of the colored heavy metal complexcompound of the final image is greater than that of the first solubleheavy metal complex compound.

The process according to the invention requires a photographic layerwhich contains silver halide in imagewise distribution. Such a layer canbe produced in various ways depending on whether a positive or negativeimage of the original is required. In the former case, an exposed silverhalide emulsion layer is developed in the usual manner, a negativesilver image of the original being obtained. The silver halide remainingin the layer then forms a positive, invisible silver halide image of theoriginal.

Ifone has to start with a negative silver halide image, exposure anddevelopment are first carried out in the usual manner as describedabove, the silver halide remaining in the layer is then removed byfixing, and lastly the silver image is converted into silver halide.

For the sake of better understanding, the principle of the inventiveprocess will be explained in the following by means of a specificexample. A layer which contains silver halide in imagewise distributionand contains uniformly distributed in diffusion-resistant form anorganic compound, which forms a dye with free nickel ions, is firstreacted with a solution of Ni(CN) complex compound. Since thedissociation constant of the complex compound is greater than that ofthe corresponding silver cyanide complex compound, the nickel complexcompound is destroyed in those areas where silver halide is present, andnickel ions are liberated in these image areas. The organic complexforming agent referred to above now reacts with the free nickel ions toform the image dye in these areas. This dye image is exactlyproportional in its density to the silver image. This is due to the factthat on formation of the silver cyan complex compound, thestoichiometric quantity of nickel ions is liberated.

As already explained above, the relationship between the dissociationconstants of the first heavy metal complex agent, the correspondingsilver complex agent and the colored heavy metal complex agent of thefinal image is important in the process according to the invention. Therequired relation between the dissociation constants of the complexescan easily be adjusted by suitable choice of heavy metal ions, theligands of the first heavy metal complex, and the organic complexforming agents which yield with the liberated heavy metal ions the finalimage dye. Since innumerable heavy metal complexes with inorganic andorganic ligands are described in the literature, a person skilled in theart can easily find combinations which meet the required conditions.

The three components essential for the process according to theinvention are as follows:

1. Heavy metals: suitable are auxiliary group elements of the periodicsystem of elements, especially of the first, sixth, seventh and eighthauxiliary group; e.g., copper, chromium, manganese, iron, cobalt,nickel, palladium and platinum. Copper, iron, cobalt and nickel areespecially suitable for reasons of cost and owing to suitable colortones of their complex compounds.

2. Suitable ligands for the original heavy metal complex compoundsinclude cyano-, thiocyanato or thiosulfate ions, aliphatic andheterocyclic amines or polyamines, complex forming amino-carboxylicacids such as ethylenediaminotetraacetic acid or nitrilotriacetic acid.By the term ligands is meant groups which are attached directly to theheavy metal central atom.

3. Complex forming agents or ligands for the complex which forms thefinal image dye, are shown in the following tables: 5

TABLE 1 Nickel-(Il)ion Organic complex forming agent Color -yor syn formof dioximes of l,2-diketones yellow -y-benzil dioxime yellow'y-methyldecylglyoxime yellow Dlisonitroacetone and derivatives thereofyellow Mercaptobenzothiazole and its derivatives dark yellowDicyandiamidine and derivatives thereof yellow Dimethylglyoxime magentaCyclohexandiondioxime magenta a-or anti-benzildioxime magentaa-furildioxime magenta Nitrosoguanidine magenta Bis-(diacetylmonoxime-imino )-propane-l ,3 magenta Bis-(diacetylmonoxime-imino )-ethane-1 ,2 magenta Diphenylcarbazide magentato blue-violet l,2-diamino-3 -sulfo-anthraquinone dark blueTriethanolamine blue o-aminobenzoic acid green S-chlorosalicylicaldoximegreen Acetaldoxime cyan Benzaldoxime V cyan Phenylthiosemicarbazide darkgreen o-hydroxyacetophenonoxime green TABLE 2 lron-(II)-ion rgamccomplex forming agent Color Pyridine-Z-carboxylic acid yellowa,ct-dipyridyl red Dimethylglyoxime red Thioglycolic acid red-violetQuinoline-8-carboxylic acid red Nitrosoguanidine magenta2-nitroso-l-naphthol-4-sulfonic acid green Triethanolarnine greenPhenanthrenequinonemonoxime blue-green 5 5 lsonitroacetylacetone blue4-isonitroso- 1 -phenyl-3 -methyl-pyra.zolone-5 bluea-nitroso-fl-naphthol green TABLE 3 0 lron--(Il'l)ion Organic complexforming agent Color Kojic acid yellow-orange Acetylacetone redl-(thenoyl-[a )-3,3,3-trifluoracetone H COCH COCF red s 7 V 7 V ,74-dimethylamino-1-phenyl-2 ,3- dimethylphrazolone:(5) blue TABLE 4Copper-(D-ion Color Zinc diethyldithiocarbamate brown-yellow2,2'-diquinolyl magenta l l0-phenanthroline blue TABLE 5 Copper-(Il)ionOrganic complex forming agent Color Antipyrine lemon yellowSalicylicaldoxime yellowish Schloro-salicylicaldoxime yellow-brownMercaptobenzothiazol pale orangeyellow Sodium diethyldithiocarbaminateyellow Diethylaminodiethyldithiocarbaminate orange Dicyandiamidine redMonoethylphthalate cyan Glycine blue Diethanolamine blue Triethanolamineblue Phenylthiosemicarbazide deep blue Quinoline indigo bluea-benzoinoxime green Diisonitrosoacetone dark green Acetaldoximeluminous blue Acetone Dicarboxylic acid oxirne green1,2-diaminoanthraquinone-3-sulfonic acid blue Quinaldic acid cyanPhenylglyoxalic acid oxime luminous green TABLE 6 Cobalt--(ll)-ionOrganic complex forming compound Colorl-(thenoyl[a']-3,3,3-trifluoroacetone orange2-nitroso-I-naphthol-4-sulfonic acid red a-benzilmonoxime redDiisonitrosoacetone red Phenylglyoxalic acid oxime redl,Z-diamino-anthraquinone-3-sulfonic acid green-blue quinoline blueS-nitrosalicylicaldoxime green Acetonedicarboxylic acid oxime greenAcetone oxirne cornflower blue Mercaptobenzothiazol greenphenylthiosemicarbazide green l-( 2-pyridyl-azo )-2-naphthol cyan TABLE7 Platinum Organic complex fonning agent Color Z-mercaptobenzothiazolecanary yellow Thionalide yellow Dithiooxarnide Benzidine magenta greenDimethylglyoxime Cyclohexanedionedioxime orange-yellow Orange-yellowa-nitroso-fi-naphthol violet p dimethylaminobenzylidene thioxyanatered-violet suitably substituted formazanes cyan The process of theinvention is characterized by applying a photographic materialcomprising at least one layer which contains silver halide in imagewisedistribution and which further contains uniformly distributed in thesilver halide or another layer adjacent to the said silver halide layerthe organic complex forming agent fast to difl'usion.

The organic complex forming agent is added in a diffusionresistant formto the silver halide emulsion layer, or to an adjacent layer, in amanner well known in the art. This can be accomplished in the same wayas the diffusion'fast incorporation of color couplers in conventionalcolor photography. The organic complex forming agent may either besubstituted by long chained alkyl radicals having about 12 to 18 carbonatoms and a solubilizing group such as sulfo groups, or it may bedissolved in an organic solvent and emulsified in the photographiclayer. In the latter process, high boiling solvents, socalled oilforming agents, may be added in known manner.

The present invention is preferably used for producing multi-layeredmaterials according to the subtractive color principle. These materialsare similar in structure to the known color photographic multi-layermaterials except that the conventional color forming system consistingof color couplers capable of reacting with the oxidation products ofcolor-forming developers is replaced by the system according to theinvention which consists of the solution of the heavy metal complex andthe diffusion resistant organic complex forming agent in thephotographic layer.

A photographic material which is operative in the process of the presentinvention consists of a blue-sensitive silver halide emulsion layerwhich contains an organic complex forming agent in a diffusion-fast formwhich yields a yellow dye with a heavy metal ion, a green-sensitivesilver halide emulsion layer which contains an organic complex formingagent in a diffusion-fast form capable of forming a magenta dye with theheavy metal ion, and lastly, a red-sensitive silver halide emulsionlayer which contains an organic complex forming agent in diffusion-fastform capable of forming a cyan dye with the heavy metal ion.

The above mentioned organic complex forming agents, especially thosewhich yield a magenta or cyan dye, include some which have a yellow tored color of their own. These complex forming agents are of specialimportance in that they act as integral masks for eliminating undesiredside-absorptions of magenta or cyan dyes. The principle of masking iswell known in the art of color photography.

The invention, in the form described earlier using nickel as heavy metalion is based on the fact that the stability of the silver cyanidecomplex is higher, or in other words the dissociation constant is lowerthan that of the nickel cyanide complex. Silver halides are, therefore,capable of displacing nickel ions from the cyanide complex. Numerouscombinations of heavy metal ions, inorganic and organic complex formingagents are already known which would be suitable as regards the dyeformed, but these cannot be used in the described simplified form of theprocess according to the invention because the dissolved inorganic ororganic heavy metal complex is more stable than the corresponding silvercomplex. In such a situation the silver would not be capable ofdisplacing the heavy metal ions from the soluble complex compound. Thisapplies, for example, to the iron cyanide complex compounds which have ahigher stability than the silver cyanide complex. Silver halide is,therefore, not capable of liberating iron ions from the cyanide complexat room temperature. However, since iron ions would themselves besuitable, especially since numerous organic complex forming agents areknown which react with iron ions to yield dyes of subtractive colors,yellow, magenta or cyan, the use of these heavy metal ions is verydesirable. This system can, in fact, be used by slightly modifying theprocess according to the invention. In the modified process, the silverhalide image is converted into a mercury salt image in a manner which iswell known in the art. Since the mercury cyanide complex has a muchlower dissociation constant than the iron cyanide complex, the processcan now be carried out in the manner described.

The direct use of suitable heavy metal complexes is only possible if thecomplex forming agent (ligand of the first soluble complex) is so chosenthat the silver ion is capable of displacing the heavy metal from thecomplex compound.

In general, any heavy metal ion that yields the color triplet yellow,magenta and cyan with suitably selected organic complex forming agents,may be used in the process of the present invention. The heavy metalions must first form a first complex compound which is sufiicientlystable so as not to react with the organic complex fonning agent in thelayer. It is only after liberation of the heavy metal ion by a secondmetal ion, preferably silver, which has a greater tendency to fonn acomplex compound with the ligands of the first complex that the desiredcolored heavy metal complex agent of the final image is formed. A fewfigures may serve as examples. The dissociation constant of the mercurycyanide complex is 4 X 10", that of the ferrocyanide complex is l0'Mercuric chloride, therefore, displaces ferrous ions from theferrocyanide complex. The ferrous ions liberated can react with theorganic complex forming compounds to yield the appropriate dyes.

The dissociation constants of the colored heavy metal complexes of thefinal image are substantially higher and are probably of the order of10" to l0". For example, in the simplest case, namely the displacementof nickel ions from the nickel cyanide complex by silver ions, thedissociation constants of the different silver cyanide complexes are ofthe order of 10 to 10', whilst the nickel cyanide complex has adissociation constant of about 10' so that the silver salt can displacenickel ions from its cyanide complex compound. The free nickel ions thenreact with the organic complex forming agent, and the dissociationconstant of the complex compounds thus formed being presumably in theregion of 10' to 10 The main advantage of the process described above isthe high fastness to light of the complex compounds forming the finalimage. Light-fastness values are achieved which are multiples of thoseobtained by azomethine dyes of the conventional color photographicprocesses. The process is suitable for a negative process as well as apositive or reversal process. Furthermore, automatically masked colorednegatives can be obtained by applying originally colored organic complexfonning agents.

In another variation which may be employed for obtaining maskednegatives, the organic complex forming agents at the areas which in theoriginal silver halide image were free from silver halide and whichaccordingly have not undergone reaction with heavy metal ions arereacted with a suitable heavy metal salt solution wherein the heavymetal is different from that of the first heavy metal complex to formthe masking dye. For example, a dicyandiamidine derivative incorporatedin a difl'usion-fast manner reacts with copper to form a magenta imagedye, and after treatment with a nickel salt solution the complex formingagent that has not been usedup yields a yellow masking dye in the areasthat have not been exposed to light.

The concentration of organic complex forming agent in the silver halideemulsion layer may vary within, wide limits according to therequirements of the reproduction process and the properties of thephotographic material. A ratio of concentrations of the organic complexforming agents to the silver present of about 1 mol to 1 mol hasgenerally proved suitable. The valency of the heavy metal cation is oflittle influence in this respect since monovalent cations are usually intwofold coordination, bivalent cations are usually in four-foldcoordination and trivalent cations are usually in sixfold coordination,provided, of course, that the organic complex forming agent has twopositions for coordination on the metal, which is practically always thecase.

The silver content of the emulsion layers depends to a certain extent onthe valency of the cation used for production of the image dyes. Thus 2mols of silver are required for liberating a bivalent cation, 3 mols ofsilver for liberating a trivalent cation etc. In general quantities ofbetween 0.5 to 10 g. silver in the form of silver halide per squaremeter per layer have proved sufficient.

Example 1 Production of a negative magenta image:

20 g. of -y-benzildioxime are dissolved in 300 ml. of

per liter of solution ready p-methylaminophenol l g. anhydrous sodiumsulfite 13 g. hydroquinone 3 g. borax 20 g. potassium bromide l g.

The developed material is treated for one-half minute in a 2 percentaqueous solution of acetic acid. The film is then fixed for 2 minutes inan acid fixing bath and thoroughly washed with water. Thereafter, thesilver image is bleached for minutes in a bleaching bath which containsg. of potassium bromide and 50 g. of potassium hexacyanoferrate (lll)per liter, and it is thoroughly washed with water.

The image thus bleached and thoroughly washed is now immersed in asolution of 5 g. of potassium nickel cyanide in 500 ml. of water.

A few ml. of concentrated ammonia solution are advantageously added tothe solution to accelerate the reaction. A magenta dye image is formedin the image areas that contain silver halide. After a treatment time of10-15 minutes, the dye image does not undergo any furtherintensification. The paper is thoroughly washed with water and is againfixed with a fixing bath usually employed to remove unreacted silverhalide. Finally the material is washed with water. An excellent negativemagenta image of the step wedge is obtained.

If the 'y-benzildioxime is replaced with the equivalent amount ofo-hydroxybenzophenone oxime and otherwise identical technique, a greenimage is obtained.

Example 2 Production of a positive yellow image:

200 mg. of an organic complex forming agent of the following formula:

are dissolved in 200 ml. of ethanol and ml. of N-sodium hydroxide. Thesolution is slowly added with vigorous stirring to 400 ml. of a 4percent aqueous gelatin solution, containing 0.2 g. of saponine aswetting agent. An emulsion of the organic complex forming agent in theaqueous gelatin solution is obtained.

The above emulsion and 50 ml. of n-succinic acid are added to 800 ml. ofa silver bromide iodide gelatin emulsion. The

' mixture is applied onto a support of cellulose triacetate.

The dried material is exposed behind a step wedge as described inExample 1, developed in the same developer solution and thoroughlyrinsed. In this case it is not fixed but the remaining residual silverhalide is converted into a yellow dye image by treatment with the samepotassium nickel cyanide solution as in Example 1.

The remaining silver halide is thereby converted into a positive yellowdye image. After this treatment, the paper is thoroughly washed withwater, and the silver formed on exposure and development is removed bybleaching in the beaching bath describedabove and the image is fixed.After a final washing with water, a positive yellow image is obtained.

The fastness to light of the resulting yellow dye is practicallyinfinite compared with the light-fastness of azomethine dyes produced bycolorforming development. After an exposure time which is five times aslong as that required to destroy an azomethine dye image obtained bycolor-forming development, no change is detected with the yellow dyeobtained according to the invention Example 3 Production of the organiccomplex forming agent:

A nitroso group is introduced into methylundecylketone by reaction withamyl nitrite with the addition of a small quantity of hydrochloric acid.The resulting Methyl-isonitrosoundecylketone is reacted withhydroxylaminein alcoholic solution to form methyldecyldiketodioxime. Theresulting product has a melting point of 149 C. after recrystallizationfrom methanol.

20 g. of the methyldecyldiketodioxime are dissolved in.300 cc. ofmethanol, and 300 cc. of a 4 percent aqueous gelatin solution containing0.5 percent by weight of the oleylether of polyethyleneglycol as wettingagent, are slowly added with vigorous stirring. An emulsion of theorganic complex forming compound in the gelatin solution is obtained.

The emulsion is added to a photographic silver bromide gelatin emulsionin such a proportion that the molar ratio of silver to complex formingagent obtained is 1:1. This solution which is ready for casting, isapplied onto a barytacoated paper.

It is exposed behind a step wedge and processed as described in Example1 or 2.

An aqueous solution of potassium nickel tetracyanide is used for formingthe dye image. The solution contains 10 g. of potassium nickeltetracyanide per liter. Further treatment is carried out as described inExample 1 or Example 2. A negative or positive yellow dye image isproduced.

The final dye image of the step wedge is exposed to daylight for aperiod of about 1 year without any noticeable bleaching. For comparison,several yellow azomethine dye images produced by conventional colorphotographic processes were subjected to the same exposure. Theazomethine dye images were completely bleached after exposure for 1year.

We claim:

1. A process for the production of colored photographic images wherebythe final image dye consists of colored heavy metal complex compounds,said process including the steps of preparing a photographic materialcomprising at least one emulsion layer containing therein imagedistributed silver halide said material including a uniformlydistributed diffusionresistant organic complex-forming compound in oradjacent to said silver halide layer said complex-forming compound beingcapable of forming colored complex compounds with ions of heavy metalsselected from the group consisting of nickel, iron, copper, cobalt,platinum and palladium, and being incapable of reacting with silverhalide, treating said photographic material with a solution of a firstcomplex compound of the said heavy metals having a dissociation constantgreater than the dissociation constant of the corresponding silvercomplex compound, the first complex compound thus being capable ofreacting with the image distributed silver halide to form imagedistributed free ions of the said heavy metals, and forming the coloredheavy metal complex compounds of the final image by reacting theimagewise formed free heavy metal ions with the uniformly distributedorganic complex-forming compound, thereby producing in imagedistribution the colored complex compound, the dissociation constant ofsaid colored complex compound being greater than that of the firstsoluble heavy metal complex.

2. The combination of claim 1 in which the organic complex-formingcompound has a color different from that of the final heavy metalcomplex and acts as a mask.

3. The combination of claim 1 in which after the final heavy metalcomplex is formed the layer is treated with a different heavy metal thatforms with the residual organic complexforrning compound a differentlycolored complex which acts as a mask.

4. In the process of claim 1 the step of first converting the silverhalide image to a mercury salt image and then reacting said mercury saltimage with said first complex compound to thereby form free heavy metalions and a complex mercury compound, and finally reacting said freeheavy metal ions with the uniformly distributed organic complex-formingcompound.

5. Colorphotographic material having on a support at least one layer oflight-sensitive silver halide emulsion in which the silver halide is inintimate contact with a uniformly distributed organic complex-formingcompound selected from the group consisting of an oxime, anaminocarboxylic acid, an amino anthraquinone, mercaptobenzthiazone,diphenylcarbazide, phenyl-thiosemicarbazide, thioglycolic acid, kojicacid, monoethylphthalate, dipyridyl, diquinolyl, phenanthroline,dicyanodiamidine, triethanolamine, nitrosoguanidine, an 1,3- diketone,antipyrine, 4-dimethylaminol -phenyl-2,3- dimethylpyrazolone-(S),diethyldithiocarbamate, quinoline, thionalide, dithioxamide andbenzidine capable of forming colored complex compounds with free heavymetal ions, the quantity of complex-forming compound being 1 mol per molof silver halide present.

6. The combination of claim 5 in which the aminocarboxylic acid isglycine, o-aminobenzoic acid, pyridine-2-carboxylic acid,quinoline-8-carboxylic acid or quinaldic acid.

2. The combination of claim 1 in which the organic complex-formingcompound has a color different from that of the final heavy metalcomplex and acts as a mask.
 3. The combination of claim 1 in which afterthe final heavy metal complex is formed the layer is treated with adifferent heavy metal that forms with the residual organiccomplex-forming compound a differently colored complex which acts as amask.
 4. In the process of claim 1 the step of first converting thesilver halide image to a mercury salt image and then reacting saidmercury salt image with said first complex compound to thereby form freeheavy metal ions and a complex mercury compound, and finally reactingsaid free heavy metal ions with the uniformly distributed organiccomplex-forming compound.
 5. Colorphotographic material having on asupport at least one layer of light-sensitive silver halide emulsion inwhich the silver halide is in intimate contact with a uniformlydistributed organic complex-forming compound selected from the groupconsisting of an oxime, an aminocarboxylic acid, an amino anthraquinone,mercaptobenzthiazone, diphenylcarbazide, phenyl-thiosemicarbazide,thioglycolic acid, kojic acid, monoethylphthalate, dipyridyl,diquinolyl, phenanthroline, dicyanodiamidine, triethanolamine,nitrosoguanidine, an 1,3-diketone, antipyrine,4-dimethylamino-1-phenyl-2,3-dimethylpyrazolone-(5),diethyldithiocarbamate, quinoline, thionalide, dithioxamide andbenzidine capable of forming colored complex compounds with free heavymetal ions, the quantity of complex-forming compound being 1 mol per molof silver halide present.
 6. The combination of claim 5 in which theaminocarboxylic acid is glycine, o-aminobenzoic acid,pyridine-2-carboxylic acid, quinoline-8-carboxylic acid or quinaldicacid.